Strip it down again as just might be the motor brushes worn out and should be cheap to replace
I did take the brushes out and examine them.... I then put them back in as I don't know what a worn motor brush looks like!
Plenty on them though and the vac completely ground to a halt when attached to a jigsaw. Dry filter in place as well.
I had a mask on and the blades were burning out when cutting cement board so I didn't notice if the vac was burning as well. It was only when I went down two flights of stairs that I noticed I was smelling like Guy Fox!